Ahoy mateys! It's not unusual to see the Columbia docked, since it seems to only operate when the park is crowded. This slide is dated October 1958, and the Columbia began it's operation in June of that same year. I'm not sure if this photo shows some early rehab work being done, or perhaps the picture was taken before the ship opened to the public, and the photographer waited a few months to develop his film.
There are a few interested onlookers watching a guy in a wetsuit at the back of the boat (I mean the stern!). For the sake of authenticity, he is probably wearing the same sort of wetsuit that was worn in the 1880's! There are some construction walls behind those onlookers, any idea what those are for?
The Columbia is a unique attraction, and certainly is a reflection of Walt Disney's interest in American History (not to mention his faith that guests would be interested as well). It's hard to imagine anything like this being built for an amusement park today...as beautiful as the ship is, there are no thrills, no character or movie tie-ins.